For example, as a grommet for vehicles such as an automobile, a conventional grommet that is externally mounted to a group of wires of a wire harness and is attached to a through hole formed in a vehicle body panel has been known. The grommet serves the function of protecting a portion of the group of wires of the wire harness that passes through the through hole, and sealing the through hole by being fitted to the through hole.
For example, the grommet described in JP 2015-202847A includes an attachment portion that is fitted to a through hole of a panel, and a tubular portion provided so as to extend in one direction from the attachment portion. The attachment portion has a shape that can be fitted to an opening edge portion of the through hole, and has a wide opening on the front side in the direction of attachment to the panel (the side opposite to the tubular portion). Since the attachment portion has a wide opening, wires can be easily passed through this opening.